Abrading device for grinding-machines.



G. POINTON.

ABRADING DEVICE FOR GRINDINd MACHINES.

APPLICATION FILED MAR.17,1913.

Patented June 16, 191.4,

ull! Hill-mu George Pointcm Witwmoeo ado cum, a

COLUMBIA PLANOGRAPK C0 WAIHINGIDN, D. C.

UNITED sT 'rns PATENT OFFICE.

GEORGE POINTON, 0F TORONTQ, ONTARIO, CANADA.

ABRADING DEVICE FOB GRINDING-MACHINES.

Specification of Letters Patent. Patented J 1111 16, 1914 Applicationfiled March 1?, 1913.

Serial No. 754,916.

of Ontario, Canada, have invented certain.

new and useful Improvements in Abrading Devices for Grinding-Machines;and I do declare the following to be a full, clear, and

exact description of the invention, such as will enable others skilledin the art towhich it appertains to make and use the same.

This invention relates to improvements in abrading devices for grindingmachines.

One object of the invention is to provide a device of this characterhaving an abrasive surface constructed of a plurality of pieces of emerycloth or the like of such shape that they may be cut from narrow stripsand scraps of material with very little waste thereby affording aconsiderable saving of material and reducing the cost of renewing thedevices.

Another object is to provide an abrading device having its abrasivesurface formed of small suitably shaped pieces of material smoothly andfirmly secured thereto without forming blisters and which are so spacedfrom each other as to leave clearance channels between them.

With these and other objects in view, the invention consists of certainnovel features of construction, and the combination and arrangement ofparts as will be more fully described and claimed In the accompanyingdrawings; Figure 1 is a bottom plan view of an abrading deviceconstructed in accordance with my invention; Fig. 2 is a side viewthereof; Fig. 3 is a plan view of a strip of abrasive material showingthe manner in which the abrasive sections are cut therefrom forapplication to the disk and whereby the greatest number of sections maybe cut from the strip with the least possible amount of waste.

My improved grinding device comprises a flat disk 1 which may be of anysuitable shape and which is here shown as of cir-- cular form and ashaving a centrally disposed passage or socket 2 to receive the meanswhereby the disk is fastened to the grinding machine. To the lowersmooth and uninterrupted flat face of the disk is glued, cemented orotherwise firmly fastened sections 3 of abrasive material such as emerycloth, paper or the like. The sections 3 may be of any suit-able sizeand shape and any desired number of sections may be provided forcovering the working face of the disk. In the present instance the diskis shown as having secured thereto four sections or pieces 3 of abrasivematerial, said sections or pieces being cut in se'ctor shape and securedtothe working surface of the disk as shown, whereby radial channels 4are formed bet-ween adjacent sectors, leading from the inner pointedends 5 of the same, along-and between their straight sides 6, to theirouter edges 7 which are preferably coincident with the periphery 8 ofthe disk. These channels afford clearance for the particles which areground off from the surface of the object treated, and clearance forparticles of the abrasive material itself. The sections 3 arefurthermore cut in sector shape to facilitate the cutting thereof fromnarrow strips M of material with the least possible amount of waste, asclearly shown in Fig. 3 of the drawings, and which enables the largestnumber of sections to be cut from the strip. I do not, however, wish tobe understood as confining myself exclusively to sector shaped sectionsas it is obvious that the sections may be formed in other shape,although I prefer that they have pointed inner ends 5 directed towardthe center of the device and I prefer that the channels 4. between thevarious sections shall be substantially radial and shall in no case growsmaller toward the periphery of the device. The obvious reason for thispreference is between the points 5 no space is leftwhere the materialmight accumulate near the center, such as would be the case if thepoints were cut off on arcs struck around said center. The centrifugalforce tending to drive said material and the particles thereof towardthe periphery of the disk, is of course least at the center of thedevice, and when such a space occurs there I find that the material isquite likely to accumulate. As for the radial channels, if the device isconstructed as shown and described these channels are of a uniform sizethroughout their length and are strictly radial. In any event I wouldhave them approximately radial and they should not grow smaller towardthe periphery. The advantage of these channels is that in the rapidrotation of the device, the particles of the material acted on and theparticles of the grinding surface tend to flow outward along thesechannels by reason of centrifugal force. In applying the sections to thedisk it will also be obvioi s plurality of small pieces or sections,saidsections; may be secured to the face of the disk without. blistersbeing formed which frequently occurs in devices; of this character when;the abrasivematerial is secured to the disk in one piece. The forming ofthe grinding surface in sections also permits one or f more sections to.be removedand replaced by new sections when they are Worn, without;requiring the removal and renewal of the entire, abradingmaterial as isnecessary inthe form of; abrading devices now in use when one. part ofthe abrading surface becomes worn before theother parts thereof. Fromthe foregoing description taken in connection with the accompanyingdrawings, the construction. and operation of the invention will bereadily understood without requiring a more extended explanation.

Having thus described my invention, what I claimvis:

The herein described abrading device comprising a disk having a fiatsurface and adapted to be rotated on its axis in the nesses.

GEORGE POINTON. Witnesses VERA SHERMAN, M. SrRAcH-AN.

Copies;ot thiapatentr,may.be. obtainedfor five cents each, by addressingthe; Commissioner of ZPatents, Washington, I). 0.

